The Kingdom of Lydia was a state that existed in much of western and central Anatolia from the late Bronze age to the Classical era. Begun as a Hittite entity, Lydia would become the most powerful native Anatolian state since the fall of the Hittite Empire in the Bronze Age Collapse.

For much of its history the Lydian Empire existed as a merely occupational state, rarely expanding against either the Medians to the east or the Ionian Greek city-states to the west. This would change during the reign of Croesus, who decided to cross the river Halys and claim some of the western lands of the crippled Median Empire, weak from war with the upstart Persians. Croesus and Cyrus soon battled each other to a draw in Cilicia, ending Persian expansion west and Lydian expansion east.

Over the next few decades, Croesus and his successors began to expand west, conquering the Ionian cities one by one and crossing Propontis into Europe. The Thracians put up limited resistance but capitulated all the same. As Macedonia pledged fealty to the Lydians, the stage was set for a possible invasion of the Greek homeland.

However, the Greeks would be the ones to strike first. Angry at the subjugation of their Ionian cousins, the Athenians sponsored a revolt against Lydian authority in 499. These revolt was easily crushed by the Lydians, but a punitive expedition to punish the Athenians failed at the Battle of Marathon in 490. Furious at this defeat, the Lydians began preparations for a larger expedition to subjugate the entirety of Greece. Launched in 481 from Macedonia, this expedition was soon beaten by the united Spartans and other Greeks at the Battle of Thermopolyae in 480 despite some naval victories at the same time. A Greek victory at the Battle of Mycale the next year freed the Ionian cities and forced Lydian withdrawal from much of Europe and Hellenic affairs.

Perhaps this was just as well, for the Persians under King Xerxes invaded Lydia in 465, seeking to expand further west and take advantage of perceived Lydian weakness. Although somewhat recovered since the war, the Lydians were slowly pushed back to their capital. At a final stand in the Battle of Thymbra in 461, the Lydians killed Xerxes and pushed the Persians all the way past Cilicia, preventing their own conquest and creating considerable disorder within the Persian Empire for several years.

Eventually, however, Lydian security would not last. Tensions with the Greek states and a constant fear that Lydia would invade again led to many Greek attempts to check Lydia's power. When Alexander the Great came to the throne in Macedonia in 336 BC, he launched a campaign to unite all the Greeks in the world against the Lydians for revenge. The Lydians were crushed in 334 and their capital of Sardis was sacked. Lydia had fallen to Alexander and would remain a component of his Empire for many decades, although surviving Lydian noblemen had some role in the establishment of the native Kingdom of Cappadocia shortly after Alexander's death.